What I found is, every rifled shotgun I have used, likes certain slugs and will get great accuracy with one or maybe two.
My Remington 1100 gets 2 1/2 inch groups at 100 yards with the Remington solid copper slugs. 2 3/4 inch
My Baretta Extream gets 2 1/2 inch groups at 100 yards with Lightfield slugs 2 3/4 inch.
My Remington 870 Wingmaster with a hastings rifled barrel also shoot the Lightfields very well, about 3 inch groups at 100 yards.
I am going to the range with my Encore barrel with lightfields, I have shot it at 25 yards, and I just get one ragged hole, so it is out to the range to do some 100 yard shooting with it.
I have shot a bunch of different shotguns, and it is just trial and error to find what shoots best in each.